tailieunhanh - The effect of residual la on crystal structure and magnetic properties of La1+ơFe11.05Si1.95 Compounds

In this paper, we present the results of the study of the effect of residual La on crystal structure, magnetic properties of La1+ (ơ= ; ; and ) compounds. The analysis of X-ray diffractions showed that when the La content increases to 9, the structure still remains cubic in a typical NaZn13 arrangement with unchanged lattice constant (about ). | VNU Journal of Science Mathematics Physics Vol. 36 No. 3 2020 100-105 Original Article The Effect of Residual La on Crystal Structure and Magnetic Properties of La1 Compounds Vuong Van Hiep1 Do Thi Kim Anh1 Ngac An Bang1 Sai Cong Doanh1 Nguyen Duy Thien1 Huynh Dang Chinh2 Pham Duc Hanh3 1 Faculty of Physics VNU University of Science 334 Nguyen Trai Thanh Xuan Hanoi Vietnam 2 Department of Inorganic Chemistry Hanoi University of Technology 1 Dai Co Viet Hanoi Vietnam 3 Vietnam Institute for Building Science and Technology 81 Tran Cung Nghia Tan Hanoi Vietnam Received 16 June 2020 Revised 04 July 2020 Accepted 15 July 2020 Abstract In this paper we present the results of the study of the effect of residual La on crystal structure magnetic properties of La1 and compounds. The analysis of X-ray diffractions showed that when the La content increases to 9 the structure still remains cubic in a typical NaZn13 arrangement with unchanged lattice constant about . All compounds exihibit ferromagnetic paramagnetic phase transitions. The Curie temperature TC increases slightly from 235 to 245 K. Keywords NaZn13-type cubic structure Magnetocaloric materials. 1. Introduction Potential materials applicable in magnetic cooling due to low cost simple fabrication technology and large magneto-caloric effect MCE such as Gd5 Si1-xGex 4 1 MnAs MnFe P1-xAsx 2 Heusler alloys Ni-Mn-Ga 3 perovskite ABO3 4 . have attracted the attebtion of many research groups in the world. The LaFe13-xSix compounds with NaZn13 type cubic structure is the one of these materials. Recently a number of studies on structure and magnetic properties of NaZn13-type compounds have been published 5-10 . After crystallization the LaFe13-xSix compounds exihibit the cubic structure of NaZn13 type with 1 x Ce2Ni17Si13 tetrahedra structure with x 5 and both above types for x 11 . The Fe Si ratio affects not only the crystal structure but also the ________